Impingement cooling systems have been used with turbine machinery to cool various types of components such as casings, buckets, nozzles, and the like. Impingement cooling systems cool these components via an airflow so as to maintain adequate clearances between the components and to promote adequate component lifetime. One issue with some types of known impingement cooling systems, however, is that they tend to require complicated casting and/or structural welding. Such complicated structures may not be sufficiently durable and/or they may be expensive to produce and repair.
By way of example, an impingement cooling insert may be positioned within a nozzle airfoil cavity. Nozzle ribs may be machined into the cavity for positioning the cooling insert therein. The ends of the ribs may need to be machined to achieve a proper interface for welding or brazing the cooling insert therein. Such procedures are generally time consuming and expensive. Moreover, part life may be reduced due to air leakage across the joints or otherwise.
There is thus a desire for an improved turbine nozzle. Preferably such an improved turbine nozzle may provide for the fast and efficient insertion of an impingement cooling insert therein without expensive casting or machining while providing adequate cooling for a prolonged component lifetime and overall system efficiency.